From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id A336FE7C4E6 for ; Wed, 4 Oct 2023 16:49:14 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 3429E6B0260; Wed, 4 Oct 2023 12:49:14 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 2F2E36B0261; Wed, 4 Oct 2023 12:49:14 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 1BA446B0266; Wed, 4 Oct 2023 12:49:14 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id 087296B0260 for ; Wed, 4 Oct 2023 12:49:14 -0400 (EDT) Received: from smtpin08.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay02.hostedemail.com (Postfix) with ESMTP id C3F1B120382 for ; Wed, 4 Oct 2023 16:49:13 +0000 (UTC) X-FDA: 81308364186.08.969D0A8 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by imf18.hostedemail.com (Postfix) with ESMTP id 1C3E91C0024 for ; Wed, 4 Oct 2023 16:49:11 +0000 (UTC) Authentication-Results: imf18.hostedemail.com; dkim=none; spf=pass (imf18.hostedemail.com: domain of cmarinas@kernel.org designates 145.40.68.75 as permitted sender) smtp.mailfrom=cmarinas@kernel.org; dmarc=fail reason="SPF not aligned (relaxed), No valid DKIM" header.from=arm.com (policy=none) ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1696438152; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Mh+2Jtj6SSHct4tO5kQKfgIOLrUCbzP5YEOvnuyppTE=; b=zLjJQxfKacgIJS/SgDoj+/45IXkGYdIdv7dY0bpQyKDa3/MsDseLTdxIJZM7wBlVPqFUKN +Fc5q4FtItfTS2xC6Ohd1wRJUPD5yikUabdo8GeT+Pfe9o4l2jd+ipcKzhEvI6lLddL2rY DvGKfvA0EbxOZVy9jzbFAmPSWSYaZtk= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1696438152; a=rsa-sha256; cv=none; b=to0z+qqaF9Hne+bUqLfgFhTu+lIcPYBhbA/o6uUKrbbSBlixc5Qq1oLhrG4SNv+Zvi9wzh EKfFEwU1HETJI2K0CfWnOHRKLm0sNZHzyPZsrNu8o3/Z1kvdGVZoH9v8ZftLV1XXUQIB+i 5kl7uWrEan74wh9X6+/PfKVUXr6djng= ARC-Authentication-Results: i=1; imf18.hostedemail.com; dkim=none; spf=pass (imf18.hostedemail.com: domain of cmarinas@kernel.org designates 145.40.68.75 as permitted sender) smtp.mailfrom=cmarinas@kernel.org; dmarc=fail reason="SPF not aligned (relaxed), No valid DKIM" header.from=arm.com (policy=none) Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by ams.source.kernel.org (Postfix) with ESMTP id 7F989B81F5F; Wed, 4 Oct 2023 16:49:10 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 70C4DC433C7; Wed, 4 Oct 2023 16:49:07 +0000 (UTC) Date: Wed, 4 Oct 2023 17:49:04 +0100 From: Catalin Marinas To: Joey Gouly Cc: linux-arm-kernel@lists.infradead.org, nd@arm.com, akpm@linux-foundation.org, aneesh.kumar@linux.ibm.com, dave.hansen@linux.intel.com, maz@kernel.org, oliver.upton@linux.dev, shuah@kernel.org, will@kernel.org, kvmarm@lists.linux.dev, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org Subject: Re: [PATCH v1 05/20] arm64: context switch POR_EL0 register Message-ID: References: <20230927140123.5283-1-joey.gouly@arm.com> <20230927140123.5283-6-joey.gouly@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230927140123.5283-6-joey.gouly@arm.com> X-Rspamd-Queue-Id: 1C3E91C0024 X-Rspam-User: X-Rspamd-Server: rspam11 X-Stat-Signature: pygndgtrou4g6ii8wxruyziyjqtx84wx X-HE-Tag: 1696438151-717007 X-HE-Meta: U2FsdGVkX1//R15l62yBpqrW/UlcAktUcTe44DdxCAxnjgesHxCIA7l+lIb0IS5ONfFS/OJNVnMFmy0zCEE0su2nqaCgyDEN2LGgX6pin/gK6XtKDrwGpvXWpgfUoOaIDmrpLu6zwIBodLkjULfXsEx7QshExekneC9BFrRAzZimDdpvPhgWC0DnO3WzKjDXAD3GQreXY/7B564h65pglcTV+Q7GkfXDcO5lX7auXsaDmvM/jVdPUSoHOgUnNzbPLnVVbRGvBGiz/dbyIOp32PffJY5NAqG+qO9DDH5V6jgrs+PoOpPFRrlJ/sf5A6yQnmVUFqkYyAFNgNadb51Cp92/WAo2+lNY2RCdwgKCE13iFmgftC3dvkIAzJIvRFLTa+OaJqwqOWE7ZrJ+M5p1Ys2Uu9fVN4Npm2g+fCGTht5CMdjaAQkAN2NmPFMLzPzEWFRYDmseBS8WkvRybLA9t04El3UW3odaeCSvvlm48OAp7Kk+pxVAjTTA5aw1CDm+ojbdYRwwGrXspnxYnfk17RhexRrTY8MO94CXttIs5VewqKzY651u2z+8+6eGefm1tXR4pxFDmYu9Xd3BixPXeJ4QhNMIrPnD6XTBkpuWLL+SGWRopWSyUspMa0i0uTBanaIE4M2xfN9Lmd3EOCCrun8dJJNCKRvGToCG1R3AGflTBvj1tgi7+/JAxFbqCDen3FhyHqBc9Ed/CruU9ZRm44vPKkG/w1r+xFUKdHreZQof8UBVU8cRiXMKiyns8234jEsrS1xhsiYIs5pFtjm1aahBnJhgRY5TG1/O6uqBZ/2lSubAk6CZGzykPS7h6elnihKx2ZtD9/T83Q2YBGj3HWOPNRL3QTf+n9eBoijZrOp8eji2TkmpiJkkH89VelEcWANmc27/dTdGebZ29XCugxZIuk1O49k8P4LEfWk4zYf7JyHwoU/tCMzK6XnYmfkNV1mp39xgkOUSXD/TNtE SzjWzlXR aBVsT2RWeU/iWmRY0LH8gvHbj2XdI3BrVapxJmVplTaJ5OEJ69sVzb3GGmZs4orpaVO5qfPidwG6uRi8aooe7nrNEc/ts3HJX4ww7ABjmQmcGj0oKVzAjuO/QMkE0YM6M7uQzMinTul/m7U0mwZbUh2lJrQzkM2uGjtr/pboVGcPVv+VubffW0du4nWOZfQ4UqXGb5kMonOaSgJl/IolRs/cAJRPNGk9t71J/tWRWItHItXBQ/tzk86C3sfXmSfYs7g/5JeuKUZDNQ0sSG/mtgg1OMjHhWiLcbbNciXnHyvlQS3Tl8Ploxcx3ohUk1JFjV06JPyGywMK/P/mS19DpVO5wzAQYCBdHxq2ITKAtd6jSOUmOb8dvT6fJWA== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Wed, Sep 27, 2023 at 03:01:08PM +0100, Joey Gouly wrote: > +static void permission_overlay_switch(struct task_struct *next) > +{ > + if (alternative_has_cap_unlikely(ARM64_HAS_S1POE)) { > + current->thread.por_el0 = read_sysreg_s(SYS_POR_EL0); > + write_sysreg_s(next->thread.por_el0, SYS_POR_EL0); > + } > +} Does this need an ISB or is the POR_EL0 register write self-synchronising? -- Catalin